Method for the production of N-cyclic and N,N'-dicyclic ureas and their use as chemical solvents

Abstract

A process for the dissolution of chemical compounds by use of ureas in which at least one of the urea's two nitrogen atoms is part of a non-aromatic ring which can be broken by an oxygen or sulphur atom as a chemical solvent, and a method of producing tri- or tetraalkylated ureas or bis ureas wherein at least one of the urea's nitrogen atoms is part of a non-aromatic ring which can be broken by an oxygen or sulphur atom by means of dialkylating the --NH 2 group of a urea with an alkene or alkene arylene alkene dihalogenide, disulphonate or dihydrogen sulphonate in the presence of a solid base and a phase-transfer catalyst.

What we claim is: 
     
       1. A method for the production of ureas of the formula: ##STR5## in which Y represents a methylene group or an oxygen atom, m and n representing independently of one another the numbers 1 to 3, whereby n plus m represent the numbers 3 or 4, R 1  ' and R 2  ' independently of one another denote a straight-chain, branched or cyclic alkyl group having 1 to 22 C atoms, which is unsubstituted or substituted by fluorine atoms; nitro groups; alkenyl- or alkylidene groups having 2 to 6 C atoms; phenyl groups which are unsubstituted or substituted by fluorine atoms, nitro groups, alkyl groups having 1 to 5 C atoms, alkoxy groups having 1 to 5 C atoms or phenoxy groups; benzyl or phenylethyl groups which are unsubstituted or substituted by fluorine atoms, nitro groups, alkyl groups having 1 to 5 atoms, alkoxy groups having 1 to 5 C atoms or phenoxy groups; alkoxy groups having 1 to 5 C atoms; phenoxy groups which are unsubstituted or substituted by fluorine atoms, nitro groups, alkyl groups having 1 to 5 C atoms, alkoxy groups having 1 to 5 C atoms or phenoxy groups; or, together with the nitrogen atom, a five or six-member non-aromatic ring which can be broken by an oxygen or sulphur atom; R 1  ' additionally represents hydrogen, or R 1  ' represents hydrogen and R 2  ' represents a group of the formula: ##STR6## in which R 3  and R 4  have the meanings of R 1  ' and R 2  ' as described above, whereby R 3  and R 4  additionally represent hydrogen, and R 5  represents an alkylene group with 2 to 20 C atoms or an alkylene phenylene alkylene group, in which the alkylene groups independently of one another have 1 to 3 C atoms, comprising reacting a urea or a bis urea of the formula: ##STR7## in which R 1  ' and R 2  ' have the meaning as described above in the presence of a solid base and a phase-transfer catalyst in a diluting agent which is inert under reaction conditions at temperatures of 0° to 150° C. with a compound of the formula:   X-R.sub.6 -X                                               V     in which R 6  represents a straight-chain alkylene group with 4 or 5 C atoms in which the C atom can be replaced in the 2 or 3 position by an oxygen or sulphur atom, and X represents a halogen, sulphonic acid, or hydrogen sulphate leaving group, whereby the --NH 2  group of the urea of the formula IV is dialkylated by elimination of both hydrogen atoms through the compound of the formula V by elimination of the X leaving groups through ring closure.     
     
     
       2. The method as claimed in claim 1, comprising employing a urea of the formula IV in which R 1  ' and R 2  ' represent independently of one another a straight-chain alkyl group with 1 to 8 C atoms, and R 1  ' additionally represents hydrogen, or R 1  ' and R 2  ' represent together with the nitrogen atom a 5- or 6-member non-aromatic ring which can be broken by an oxygen atom.   
     
     
       3. The method as claimed in claim 1, comprising employing a compound of the formula V in which X represents a halogen atom. 
     
     
       4. The method as claimed in claim 1, comprising employing an aromatic hydrocarbon as the diluting agent. 
     
     
       5. The method as claimed in claim 1, comprising employing potassium or sodium hydroxide as the base and a quaternary ammonium salt as the phase-transfer catalyst.